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Purpose: Recent advancements in technology have led to the exploration of solar-based thermal radiation and nanotechnology in the field of fluid dynamics. Solar energy is captured through sunlight absorption, acting as the primary source of heat. Various solar technologies, such as solar water heating and photovoltaic cells, rely on solar energy for heat generation. This study focuses on investigating heat transfer mechanisms by utilizing a hybrid nanofluid within a parabolic trough solar collector (PTSC) to advance research in solar ship technology. The model incorporates multiple effects that are detailed in the formulation. Design/methodology/approach: The mathematical model is transformed using suitable similarity transformations into a system of higher-order nonlinear differential equations. The model was solved by implementing a numerical procedure based on the Wavelets and Chebyshev wavelet method for simulating the outcome. Findings: The velocity profile is reduced by Deborah's number and velocity slip parameter. The Ag-EG nanoparticles mixture demonstrates less smooth fluid flow compared to the significantly smoother fluid flow of the Ag-Fe3O4/EG hybrid nanofluids (HNFs). Additionally, the Ag-Ethylene Glycol nanofluids (NFs) exhibit higher radiative performance compared to the Ag-Fe3O4/Ethylene Glycol hybrid nanofluids (HNFs). Practical implications: Additionally, the Oldroyd-B hybrid nanofluid demonstrates improved thermal conductivity compared to traditional fluids, making it suitable for use in cooling systems and energy applications in the maritime industry. Originality/value: The originality of the study lies in the exploration of the thermal transport enhancement in sun-powered energy ships through the incorporation of silver-magnetite hybrid nanoparticles within the heat transfer fluid circulating in parabolic trough solar collectors. This particular aspect has not been thoroughly researched previously. The findings have been validated and provide a highly positive comparison with the research papers. [ABSTRACT FROM AUTHOR]

This is a numerical study of gyrotactic microorganism, heat and mass transfer futures of hybrid Williamson nanofluid made up of $ \textrm{water} - \textrm{Ag}/\textrm{MWCNT} $ water − Ag / MWCNT nanoparticles over swirling cylinder with Cattaneo–Christov heat flux. Suitable similarity transformations are presented to convert the governing partial differential equations into ordinary differential equations. The set of ordinary differential equations along with boundary conditions are solved by using the finite element technique. The sketches of swirling velocity, axial velocity, temperature, concentration and density of microorganism with individual pertinent quantities, such as volume fraction parameter of $ \textrm{Ag} $ Ag nanoparticle $ (0.01 \lt \phi 1 \lt 0.04), $ (0.01 < ϕ 1 < 0.04) , volume fraction parameter of $ \textrm{MWCNT} $ MWCNT nanoparticle $ (0.01 \lt \phi 2 \lt 0.04) $ (0.01 < ϕ 2 < 0.04) , Magnetic field parameter $ (0.1 \lt M \lt 0.7), $ (0.1 < M < 0.7) , Weissenberg number $ ({0.5 \lt \textrm{We} \lt 0.8}) $ (0.5 < We < 0.8) , Prandtl number $ ({2.2 \lt \textrm{Pr} \lt 8.2}), $ (2.2 < Pr < 8.2) , Reynolds number $ ({0.5 \lt \textrm{Re} \lt 2.0}), $ (0.5 < Re < 2.0) , Chemical reaction parameter $ (0.1 \lt \textrm{Cr} \lt 0.7) $ (0.1 < Cr < 0.7) , Peclet number $ ({0.1 \lt \textrm{Pe} \lt 0.7}), $ (0.1 < Pe < 0.7) , Bio-convection Lewis number $ (1.0 \lt \textrm{Sb} \lt 1.6) $ (1.0 < Sb < 1.6) , Biot number $ (0.2 \lt \textrm{Bi} \lt 0.8) $ (0.2 < Bi < 0.8) , thermal relaxation parameter $ (0.5 \lt \gamma \lt 2.0) $ (0.5 < γ < 2.0) and Suction parameter $ ({0.1 \lt {V_0} \lt 0.7}) $ (0.1 < V 0 < 0.7) , are depicted through graphs. Moreover, the numerical estimates of local density number of microorganisms, heat and mass transfer rates for different parameters are specified in a tabular form. The calculations show that local skin friction coefficient, Sherwood number and local density of microorganism intensify with increasing values of both volume fraction parameters $ ({\phi 1})\textrm{ } $ (ϕ 1) and $ ({\phi 2}) $ (ϕ 2). Also, the density of microorganisms and profiles of concentration are elevated in the fluid region with rising values of Weissenberg number. Temperature of hybrid nanofluid deteriorates with increasing values of thermal relaxation parameter. [ABSTRACT FROM AUTHOR]

This study investigates heat transfer rates in (AA7075-AA7072/Methanol) hybrid nanofluid flows, considering non-uniform heat sources and Cattaneo–Christov heat flux, with significant implications for aerospace engineering by enhancing thermal management in aircraft engines. The findings could revolutionize automotive cooling system efficiency, optimize heat dissipation in electronic devices, and advance the design of renewable energy systems such as concentrated solar power plants. The study aims to conduct a comparative analysis of (AA7075/Methanol) nanofluid and (AA7075-AA7072/Methanol) hybrid nanofluid flow, examining heat transfer rates, non-uniform heat sources, and Cattaneo–Christov heat flux theory around a stretching cylinder. Thermal radiation and the Biot number are also evaluated. Two different nanoparticles, AA7072 and AA7075, are used with methanol to create AA7075/Methanol nanofluid and AA7075-AA7072/Methanol hybrid nanofluid. The study compresses the resultant non-linear partial differential equation system and applies suitable similarity transformations to reduce the governing partial differential equations with boundary conditions to dimensionless form. The BVP4C shooting method in MATLAB is employed to numerically and graphically solve these dimensionless ordinary differential equations. The results indicate that higher curvature parameter values correlate with increased velocity and temperature distribution profiles. A rise in nanoparticle volume fraction reduces the radial velocity profile but increases the temperature profile. Temperature distribution profiles increase with higher thermal radiation parameter and Biot number values, while higher thermal relaxation parameter values decrease temperature. Additionally, thermal distribution profiles rise with increasing values of both the time-dependent heat source constant and space-dependent heat source parameter. [ABSTRACT FROM AUTHOR]

Activation energy is the fundamental unit of energy required to initiate chemical reactions. Some instances of initiation energy use include liquid dispersions bite dust fashioning, polymer ejection, food handling, and paper manufacturing. In view of this, the present study investigates the impact of steady, incompressible magnetized Casson–Maxwell non-Newtonian nanofluid between two stationary porous disks. The fluid movement is created by uniform injection in the direction of the axial of stationary disks. It is noticed that the thermal conductivity of the fluid varies with varying temperature. By using Buongiorno nanofluid concept the Cattaneo–Christov thermal expression is implemented. Along with this, activation energy is considered. By introducing the suitable similarity variables, the fluid model is reduced in terms of ordinary differential equations and numerical solutions are generated by using inbuild bvp4c function in MATLAB. The various dimensionless parameters impact on velocity, temperature, and concentration are presented graphically. A numerical table is presented to show the variation of local-Nusselt and -Sherwood numbers on various values of different parameters. The study reveals that improvement in Casson parameter will incline the fluid velocity, but an opposite trend is seen in the case of a magnetic field. A rise in the Brownian motion and thermophoresis parameter will enhance both temperature profiles. Improved values of activation energy will increase the concentration. The rate of heat transfer is observed more in the case of the upper disk than the lower disk. [ABSTRACT FROM AUTHOR]

After applying a magnetic field, the behavior of the partly ionized liquids is completely different from that of the ordinary fluids. In this study, we concentrated on the Cattaneo–Christov heat flux model-based three-dimensional partly ionized bio-convective flow of a second-order fluid on a bidirectional permeable stretching surface. The development of the thermal and solutal flow models takes into account the impacts of non-uniform sources and sinks, Ohmic viscous dissipation, and chemical reactions. In addition, the surface boundary effects of electron and ion collisions with convective boundary conditions are seen. The mathematical flow model is transformed appropriately to create an ordinary differential equations, which is then numerically solved with MATLAB's BVP4C approach. To demonstrate the physical relevance of the flow field along various developing parameters, graphical and tabular results are created. It is noteworthy to note that while fluid temperature decreases with stronger values of the second-order fluid parameter, fluid velocity improves in both directions. In addition, it is shown that raising the thermal and concentration relaxation parameters, respectively, causes a drop in the fluid temperature and nanoparticle concentration. [ABSTRACT FROM AUTHOR]

The interfacial nanolayer is a tinny coating of liquid molecules convened around the immersed solid nanoparticles in the base liquid, and it promises a vibrant role in improving and controlling the thermal properties of the nanoparticles and flow features when embedded in the base fluid. Hence, the current study features the consequence of interfacial nanolayer thickness during MWCNT and Au-embedded water-based hybrid nanofluid fluid over a spinning sphere. An appropriate transition is applied to rationalize the substantially paired and nonlinear governing equations and then processed by the Galerkin finite element method (G-FEM). The impression of different governing parameters on the governing systems in conjunction with entropy and Bejan number is demonstrated through graphical and tabular form. Graphs are drawn with an evaluation of general and hybrid nanofluids and different nanolayer thicknesses of nanoparticles. The thermal impact is more significant with the occurrence of Cattaneo–Christov heat flux and is supported by nonlinear thermal radiation and the Brinkman number. Entropy generation is observed to nonlinearly slow down with improvements in the Brinkman and permeability parameters, while a reverse procedure develops for the Bejan number with the above parameters. The nanolayer thickness of the nanoparticles restricted the irreversibility phenomena of the system, and the same feature is supported by the Bejan number. [ABSTRACT FROM AUTHOR]

This research aims to examine the combined effects of Cattaneo–Christov heat flux and heat generation/absorption on magnetohydrodynamic (MHD) nanoliquid (Fe3O4-Ethylene glycol) across a linearly stretchable bidirectional surface immersed in a permeable media. The characteristics of nanoliquid (viscosity and thermal conductivity) are a function of temperature and nanoparticle volume fraction. The problem is formulated by considering Corcione's correlation which describes the effective viscosity and thermal conductivity of nanoliquid. The application of Corcione's correlation on a bidirectional surface with a combination of MHD nanofluid comprising the unique combination of (Fe3O4-Ethylene glycol) makes this idea novel and is being presented for the first time. The implementation of appropriate similarity transformation leads to the transition of coupled momentum and energy equations into dimensionless ordinary differential equations (ODEs). These ODEs are numerically addressed by applying a well-known bvp4c method in MATLAB. The outcome of the arising parameters on the velocity and thermal field of nanoliquid are demonstrated graphically and numerically (drag force coefficient and Nusselt number) depicted through tables. It is observed that the porosity and velocity slip parameters combined with the volume fraction of nanoparticles decay velocity field. It is also comprehended that heat transmission augments by escalating the volume fraction of nanoparticles. A strong correlation is reflected in comparing the findings of the current analysis with the preceding literature. [ABSTRACT FROM AUTHOR]

The physiological system loses thermal energy to nearby cells via the bloodstream. Such energy loss can result in sudden death, severe hypothermia, anemia, high or low blood pressure, and heart surgery. Gold and iron oxide nanoparticles are significant in cancer treatment. Thus, there is a growing interest among biomedical engineers and clinicians in the study of entropy production as a means of quantifying energy dissipation in biological systems. The present study provides a novel implementation of an intelligent numerical computing solver based on an MLP feed-forward backpropagation ANN with the Levenberg–Marquard algorithm to interpret the Cattaneo–Christov heat flux model and demonstrate the effect of entropy production and melting heat transfer on the ferrohydrodynamic flow of the Fe3O4-Au/blood Powell–Eyring hybrid nanofluid. Similarity transformation studies symmetry and simplifies PDEs to ODEs. The MATLAB program bvp4c is used to solve the nonlinear coupled ordinary differential equations. Graphs illustrate the impact of a wide range of physical factors on variables, including velocity, temperature, entropy generation, local skin friction coefficient, and heat transfer rate. The artificial neural network model engages in a process of data selection, network construction, training, and evaluation through the use of mean square error. The ferromagnetic parameter, porosity parameter, distance from origin to magnetic dipole, inertia coefficient, dimensionless Curie temperature ratio, fluid parameters, Eckert number, thermal radiation, heat source, thermal relaxation parameter, and latent heat of the fluid parameter are taken as input data, and the skin friction coefficient and heat transfer rate are taken as output data. A total of sixty data collections were used for the purpose of testing, certifying, and training the ANN model. From the results, it is found that the fluid temperature declines when the thermal relaxation parameter is improved. The latent heat of the fluid parameter impacts the entropy generation and Bejan number. There is a less significant impact on the heat transfer rate of the hybrid nanofluid over the sheet on the melting heat transfer parameter. [ABSTRACT FROM AUTHOR]

The study of nanofluids and hybrid nanofluids is gaining conceivable importance due to their characteristics of being so useful in various daily life applications. This study deals with the motion of an electro conductive, incompressible magneto-hydrodynamic (MHD) hybrid nanofluid across a stretched surface of variable thickness. The objective of this study is motivated by a number of manufacturing and machine-building applications. However, no attempt has been made to establish MHD flow of hybrid nanofluid along a stretching sheet (a sheet with variable thickness) while keeping an eye on the impact of Hall current. In real-life situations, variable-thickness sheets are crucial in the creation of flexible containers and, additionally, in the layout and production of aerospace wings and auto body components. This study extends our fundamental knowledge of fluid dynamics and heat transmission in intricate systems. Recognizing how magnetic effects, nanofluid traits and heat conduction interplay can help researchers make valuable developments and breakthroughs in the areas of fluid mechanics and heat transfer. Hall effects are vital for applications including conductive fluids or plasma as they provide a more precise understanding of the movement of charged nanoparticles in the presence of a magnetic field. For hybrid nanofluid, we mixed the nanoparticles of titanium dioxide and copper (TiO2–Cu) into the water. Due to the low noxiousness and chemical strength of titanium dioxide-based nanoparticles, they have great uses in research. We also consider the effects of Cattaneo–Christov heat flux to analyze the heat transfer of nanoparticles and Hall current effects, which make the flow three-dimensional. For both fundamental research and real-world applications, it is of the utmost importance to take into account the Hall effects and Cattaneo–Christov heat flux in the MHD flow analysis of hybrid nanofluid over stretched surface. It makes it possible to describe the phenomenon more precisely and can enhance the effectiveness and efficiency of numerous technical procedures. By using appropriate transformations, the equations that govern the flow are transformed into a system of non-dimensional ordinary differential equations. The non-dimensional system of equations has been solved numerically by using the ND Solve command in Mathematica Software, which is based on a multistep predictor-corrector method. For velocity and temperature profiles, the interplay of numerous developing parameters on flow is depicted graphically. The Hall parameter enhances the axial velocity but reduces the transverse velocity, while the magnetic field has the opposite effects. The temperature increases with the volume fraction of nanoparticles but decreases with the thermal relaxation parameter. [ABSTRACT FROM AUTHOR]

As the primary energy source derived from the sun, solar energy is widely utilized in various technologies, including photovoltaic cells as well as the solar types of energy plates, street lights, and water pumping. This era is about studying solar radiations and a way to active enhancements in solar power pump (SWP) efficacy with the use of solar radiations and nanotechnology. Communication is structured to examine the capability of SWP in terms of transfer of heat using a hybrid nanofluid passing through a parabolic trough surface collector (PTSC) placed inside the pipeline of SWP. Solar radiation has been considered a heat source. The performance in terms of heat transfer of the SWP is scrutinized for various effects like porous media, viscous dissipation, radiative heat flux, and Cattaneo–Christov heat flux (C–CHF). Entropy generation analysis is also conducted for Prandtl – Eyring fluid (P-EF). The simulated momentum and energy equations were solved using the Keller box technique, which is a well-known numerical approach. For this work, Prandtl – Eyring hybrid nanofluid (P-EHNF) has been considered, consisting of double diverse kinds of nanotubes (NT), including single-walled carbon nanotubes (SWCNT) and multi-walled carbon nanotubes (MWCNT) in the rich, viscous fluid of kind Sodium Alginate (SA). The impact of various parameters on velocity, temperature fields, shear stress, coefficient of drag force, and Nusselt number are investigated and demonstrated in graphs and tables. The SWP experience an enhancement in the transfer of heat for amplification of the parameters of thermal radiative flow as well as viscous dissipation. In comparison with conventional nanofluid, hybrid nanofluid performs better in heat transmission. The thermal efficacy of MWCNT/SWCNT-SA over SWCNT-SA got down to a minimal level of 39.9% and peaked at 42.2%. [ABSTRACT FROM AUTHOR]

To increase energy efficiency, the flow of fluids containing nanoparticles is crucial in industrial applications notably in nuclear reactors and nuclear system cooling. In light of this, this study examines the flow of a water‐based ternary hybrid nanofluid (graphene, single‐walled carbon nanotubes, and titanium dioxide) across a curved stretching sheet with suction. The non‐Fourier heat flux model is also considered in the modeling. The existing partial differential equations are converted into ordinary differential equations through the use of similarity variables. These ordinary differential equations are then numerically solved using the Runge–Kutta–Fehlberg fourth‐ and fifth‐order method along with a shooting approach. The collection of graphical findings for the key variables on the temperature and velocity profiles is investigated. Results reveal that the heat transport in ternary hybrid nanoliquid rises as the heat source/sink parameter rises. The Biot number influences the thermal profile positively, whereas the increasing curvature parameter values reduce heat transport. The curvature parameter has a positive impact on skin friction but the suction parameter has a negative impact on skin friction. [ABSTRACT FROM AUTHOR]

Due to their capacity to create better thermal conductivity than standard nanofluids, hybrid nano-fluids and modified nanofluids have notable applications in aerospace, energy materials, thermal sensors, antifouling, etc. This study aims to the modified and hybrid nanofluid flow with the Carreau fluid over a sloped shrinking sheet. The Cattaneo–Christov heat flux also takes into account. To determine the thermal efficiency of the heat, three different kinds of nanomaterials, copper oxide ( C u O) , copper (C u) , and alumina ( A l 2 O 3 ), are used. The similarity alteration commutes the insolubility of the model into ODEs. The conclusions are attained by program writing in MATLAB software and dealing with them through the bvp4c solver with the shooting method. The skin-friction amount decreases with the inclined sheet and local Weissenberg parameter for both modified and hybrid nanofluid. An upsurge thermal relaxation parameter declines the skin-friction coefficient for modified nanofluid flow and increases the skin-friction coefficient for hybrid nanofluid flow. The heat transfer rate is upsurged with modified and hybrid nanofluid for thermal relaxation parameter. Furthermore, the presentation includes the development of skin friction coefficient and Nusselt number values for specific parameters. Through benchmarking, numerical solutions are validated using certain limiting situations that were previously published findings, and typically solid correlation is shown. [ABSTRACT FROM AUTHOR]

The present work investigates the thermophoresis and Brownian motion effects in nanofluid flow over a curved stretching sheet (CSS). Also, the Cattaneo–Christov heat flux and Stefan blowing (SB) conditions are considered for studying heat and mass transport characteristics. The present work's novelty is associated with considerations of convective boundary and SB conditions in nanomaterial flow over a CSS. The coupled partial differential equations are changed to ordinary differential equations by employing suitable similarity variables, and the resultant model is numerically handled using Runge–Kutta–Fehlberg's fourth fifth‐order method with the shooting scheme. The stimulation of the involved parameters/numbers on the flow, mass, and heat fields is broadly deliberated using suitable graphs. The present analysis's significant relevant outcomes are that the inclination in thermophoresis and Brownian motion parameters increases the heat transfer. The inclined values of the Brownian motion parameter decay the mass transfer. Furthermore, the increased values of both Schmidt number and SB parameter drop the mass transport. The increased values of the Brownian motion parameter and Schmidt number decays the rate of mass transference. [ABSTRACT FROM AUTHOR]

In this paper, we investigated the heat and mass transfer analysis of an MHD convection flow of Maxwell nanofluid with Cattaneo-Christov heat flux model along with a porous stretching sheet. The effects of thermal radiation, viscous dissipation, suction/injection, and higher-order chemical reaction are taken into consideration. By using similarity transformations the governing equations of the study are reduced into a system of ordinary differential equations and solved numerically by using the BVP5C MATLAB package. The effects of dimensionless parameters on the present study are deliberated with the aid of graphs and tables. It is found that an increase in thermal Grashof number, thermal radiation, and thermal relaxation time parameter drops the temperature field. The heat transfer rate is declined with enhancing heat source, Brownian motion and thermophoresis parameters. Also, observed that the concentration field reduces with the rising value of chemical reaction. The numerically computed values of Nusselt number and Sherwood number are validated with existing literature and found a good agreement. [ABSTRACT FROM AUTHOR]

Single-phase nanofluid heat and mass transfer futures over swirling cylinder with the impact of Cattaneo–Christov heat flux and slip effects is studied in this analysis. The effects thermophoresis, thermal radiation, Brownian motion and chemical reaction are also considered and the motion of the fluid is because of the torsional motion of the cylinder and these parameters. Suitable similarity transformations are implemented to simplify the fluid equations from partial differential equations to ordinary differential equations. The most powerful finite element technique is applied to solve the subsequent equations along with boundary conditions. Variations in the scatterings of swirling velocity, axial velocity, concentration and temperature with several pertinent parameters are portrayed through plots. Nusselt number, both components of skin friction coefficient and Sherwood number values are also examined in detail and are revealed in tables. Temperature sketches diminish in nanofluid region with rising values of heat flux relaxation number. It is detected that the nanofluids temperature deteriorates with augmenting values of temperature slip parameter. The present numerical code is validated with existing literature. [ABSTRACT FROM AUTHOR]

The current non-homogeneous nanofluid flow model is carried out to scrutinize the performance of the generalized Fourier's and Fick's laws on the MHD bioconvective aspects of couple-stress nanofluid flows through a convectively heated stretching sheet in the presence of activation energy and multiple stratified boundary conditions. Herein, both the concentrations of solid nanoparticles and motile microorganisms are incorporated explicitly into the nonlinear differential expressions describing the present non-Newtonian nanofluid flow model. Besides, the combined thermal influence of the Cattaneo-Christov heat flux and thermal radiation are also discussed. From a practical point of view, the couple-stress nanofluids are useful for examining different types of thermophysical and rheological features, since this kind of enhanced fluids can clarify realistically the dynamical behavior of various liquids, like the human blood and some polymeric suspensions. For reducing the mathematical complexity of the present physical problem, several effective similarity transformations are introduced formally to simplify the resulting partial differential equations (PDEs) into a nonlinear coupled structure of ordinary differential equations (ODEs). Moreover, the transformed dimensionless self-similarity equations are then numerically solved using the built-in shooting technique with the aid of the bvp4c solver MATLAB package. Furthermore, The obtained results are authenticated with an outstanding agreement. In this respect, the engineering quantities of interest are computed extensively with a higher level of accuracy and then summarized tabularly. To illustrate the impacts of the embedded physical parameters on the profiles of velocity, temperature, nanoparticles concentration, and microorganisms concentration, various illustrations are done successfully along with detailed elucidations. As the main findings, it is found that the temperature distribution and the microorganisms concentration profile can be enhanced with the higher values of the bioconvection Rayleigh number. Similarly, it is revealed that the nanoparticles concentration sketch and the microorganisms concentration profile can be boosted up for the higher magnitudes of the buoyancy ratio parameter. [ABSTRACT FROM AUTHOR]

Summary: A solar thermal collector collects heat by absorbing sunlight and converting this incoming radiation into useful thermal energy. The parabolic trough solar sollector (PTSC) is widely installed in concentrated solar power technology with a temperature range of 325‐700 K. The thermodynamic efficiency of the PTSC can be intensified by using nanofluids owing to their enhanced thermophysical properties. In this paper, the two‐dimensional flow over a stretched sheet in PTSC under Williamson nanofluid effects is explored. With the help of useful transformations, the partial differential equations arising from boundary layer equations of the Williamson nanofluid model are changed into nonlinear ordinary differential equations. The Keller box numerical scheme is then used to find the solution of the resulting nonlinear ordinary differential equations. Two nanofluids, copper‐engine oil (Cu‐EO) and alumina‐engine oil (Al2O3‐EO) are considered to address the performance analysis of PTSC in this study. It is observed that the parameters of the porous media reduced the heat transfer rate but increased the velocity gradient. In order to examine the effect on various performance parameters of the device, the nanoparticle concentration is also varied. With the increase in the Reynolds and Brinkman numbers, the entropy is found to increase. The thermodynamic performance of the Cu‐EO nanofluid is remarkably better than that of the Al2O3‐EO nanofluid under the same conditions. The thermal efficiency of Cu‐EO over Al2O3‐EO is seen with a minimum of 1.5% and a maximum of 9.1%. The theoretical simulations documented here may be effective in improving solar thermal energy systems. [ABSTRACT FROM AUTHOR]

The aim of the current contribution is to exploit the effects of nonlinear thermal radiation and activation energy on the flow of modified second-grade fluid with the utilization of nanoparticles. The induced flow has been considered by linear movement of stretched surface which is considered to be porous. Famous modified second-grade fluid enables one to capture the important rheological features of shear thinning and thickening. Following the modern aspects of heat and mass transportations, we have employed the theories of Cattaneo–Christov heat flux and generalized Fick's relations. The additional features of thermal radiation are also utilized in the energy equations with nonlinear expressions. Further, the impact of activation energy is also considered in the current continuation which makes the study quite versatile. While operating the suitable variables, the constituted problem has been distracted in a dimensionless form. The solution procedure has been followed with the implementation of the famous shooting technique with desirable accuracy. The involved engineering parameters are explained graphically with interesting physical consequences. It is noted that velocity distribution declined with a stretching ratio constant and combined parameter. An improved nanoparticles temperature distribution is observed with increases in stretching parameter and Brownian motion constant. The study also reports that the presence of activation energy can be more useful to enhance reaction processes. Based on the obtained scientific computations, it is claimed that the reported results can play a useful role in manufacturing processes and improvement in energy and heat resources. [ABSTRACT FROM AUTHOR]

This study explores the heat and mass transfer of Casson nanofluid flow containing gyrotactic microorganisms past a swirling cylinder. Fluid flow is generated owing to the torsional movement of the cylinder. An analysis is performed in the presence of gyrotactic microorganisms. The effects of chemical reaction, magnetohydrodynamics, heat generation/absorption, and zero mass flux condition are also considered. The Cattaneo–Christov heat flux model is initiated instead of conventional Fourier heat flux. Apposite transformations are betrothed to attain the coupled system of equations. The numerical solution is developed from the novel mathematical model via bvp4c function utilizing MATLAB software. Numerous graphs and tables are established to portray the inspiration of embroiled parameters on the flow distributions. To corroborate the presented results; a comparison to an already done published paper is also made. An excellent synchronization between the two results is obtained thus endorsing the presented model. Also, form the graphical structures and numerically erected tables, it is professed that concentration of the fluid is lessened owing to an upsurge in values of Reynolds number and Brownian motion parameter. Furthermore, diminishing density of microorganism is perceived for mounting estimates of bioconvection Péclet number. [ABSTRACT FROM AUTHOR]

The purpose of this research is to scrutinize the stagnation point flow of chemically reacting Powell–Eyring nanofluid past an inclined cylinder using the impact of activation energy with Cattaneo–Christov heat flux. Flow formulation is developed by considering the impact of nonlinear thermal radiation, binary chemical reaction, non-Fourier heat flux and the Buongiorno nanofluid model. Proper transforms yield highly nonlinear differential systems, which are solved using shooting procedure with the fourth-order R–K (Runge–Kutta) method. Comparative reviews between the formerly published literature and the current data are made for specific cases, which are inspected to be in a tremendous agreement. The narrative reviews show that the current research problem has not premeditated so far. Effectiveness of innumerable parameters is publicized graphically on velocity, temperature and concentration curves cases of various angles 0° horizontal cylinder, 45° inclined cylinder and 90° vertical cylinder. It is manifested that fluid velocity promotes with the larger values of velocity ratio. It is also noticed that concentration declines when destructive chemical reaction enhances, whilst the antithesis direction is noticed in the condition of the generative chemical reaction. Furthermore, the stream lines are closer to the cylindrical wall when α = 90° and the stream lines are far away to the cylindrical wall when α = 90°. [ABSTRACT FROM AUTHOR]

Nanofluids have the ability to flow smoothly in micro-cavities in addition with scattering of the nanoparticles. Because of the good convection between nanoparticles and the base fluid, nanofluids can achieve a good thermal conductivity. The main advantages of adding nanosize particles with base fluid are to improve the ability of storing heat, effective surface area, heat transmission, collisions and interaction among the nanoparticles. The main aim of this research work is to examine the steady and incompressible nanofluid flow between parallel rotating plates. Viscose and joule dissipation effects are taken into account. To our knowledge, impact of electrical MHD and Hall effect with Cattaneo–Christov heat flux on the squeezing 3-D flow nanofluid between parallel rotating plates are not examined yet. Heat in the form of Cattaneo–Christov heat flux is applied. We used similarity transformations to transform the primary equations to a system of ordinary differential equations (ODEs). These ODEs are then solved through the standard procedure of homotopy analysis technique. The skin friction and Nusselt number are numerically tabulated under the influence of some focused parameters. The effects produced by different parameters on the velocity (components) and temperature profiles are graphically depicted and explained in a bit detail. [ABSTRACT FROM AUTHOR]

PTSCs (parabolic trough solar collectors) are widely employed in solar-thermal applications to attain high temperatures. The purpose of this study is to determine how much entropy is created when Powell-Eyring nanofluid (P-ENF) flows across porous media on a horizontal plane under thermal jump circumstances. The flow in PTSC was generated by nonlinear surface stretching, thermal radiation, and Cattaneo-Christov heat flux, which was utilized to compute heat flux in the thermal boundary layer. Using a similarity transformation approach, partial differential equations were converted into ordinary differential equations with boundary constraints. Then, the boundary restrictions and partial differential equations were merged to form a single set of nonlinear ordinary differential equations. To obtain approximate solutions to ordinary differential equations, the Keller-Box approach is utilized. Nanofluids derived from silver- and copper-based engine oil (EO) has been employed as working fluids. The researchers observed that changing the permeability parameter reduced the Nusselt number while increasing the skin frictional coefficient. Total entropy variation was also calculated using the Brinkman number for flow rates with Reynolds number and viscosity changes. The key result is that thermal efficiency is inversely proportional to particular entropy production. For example, using Cu-EO nanofluid instead of Ag-EO nanofluid increased the heat transport rate efficiency to 15–36%. [ABSTRACT FROM AUTHOR]

• Mathematical formulation is developed using non‐Fourier heat flux model. • Water with aluminium alloy nanoparticles flow over stretching sheet is examined. • Thermal distribution is compared between Newtonian heating and common wall cases. Hybrid nanofluids are widely used in various engineering, manufacturing as well as bio-medical fields. Inspired from these applications, we discussed the flow of AA7072-AA7075/water-based hybrid nanofluid over a curved stretching sheet using non-Fourier heat flux model. Additionally, heat transference is analysed for two different boundary conditions namely, Newtonian heating (NH) and constant wall temperature (CWT). The governing partial differential equations (PDEs) are reduced into ordinary differential equations (ODEs) by opting appropriate similarity transformations. Then they are numerically solved by using Runge-Kutta-Fehlberg's fourth fifth order (RKF-45) technique by adopting shooting method. Behaviour of various parameters on flow and thermal gradients are deliberated through graphs. Also, skin friction and Nusselt number are examined graphically. Results reveal that, velocity increases for higher values of curvature parameter. Thermal distribution of assumed liquid is more in Newtonian heating case when compared to common wall temperature case for diverse values of curvature parameter and thermal relaxation parameter. The upsurge in values of curvature parameter, Newtonian heating parameter and thermal relaxation parameter improves the rate of heat transfer. Novelty of analysis: With impressed thermal performances, the nanoparticles are assumed as an effective procedure of enhancing the conductivity performances of many normal liquids. On this end, many authors performed various investigations to disclose the thermal aspects of various nanoparticles like single-walled carbon nano-tubes, multi-walled carbon nanotubes (MWCNTs), copper oxide, ferrofluid, silicon dioxide etc. However, the thermal characteristics on AA7072-AA7075/water-based hybrid nanoparticles is not analyzed and presented in the literature. This theoretical analysis access the thermal mechanism of such types of AA7072-AA7075 nanoparticles to improve the heat transfer phenomenon. A comparative analysis for improvement in heat transfer is also presented as compared to the traditional viscous materials. [ABSTRACT FROM AUTHOR]

The present work focused on two dimensional flow of an incompressible hybrid dusty fluid through a Darcy–Forchheimer medium over a stretched sheet. The Cattaneo–Christov heat flux model and the carbon nanotube properties are taken into an account. The problem is mathematically formulated from the flow, there after solved numerically with the help of RKF-45 method along with the maple package. Impacts of physical parameters of present problem such as, Eckert number, radiation parameter and Prandtl number are analyzed by means of graphs and tables with some notable applications. From the result we observed that, an escalating value of Pr diminishes the temperature profile for both fluids. Higher estimation of K p reduces the velocity profile for both phases. Momentum boundary layer thickness decreases by increasing values of F r. Furthermore, Heat transfer process is higher in dusty fluid when compare to hybrid nanofluid. And the higher radiation parameter plays a key role in cooling process. • Higher estimation of K p reduces the velocity profile for both phases. • Momentum boundary layer thickness decreases by increasing values of F r. • Heat transfer process is higher in dusty fluid when compare to hybrid nanofluid. • Higher radiation parameter plays a key role in cooling process. • Larger values of δ dismisses the temperature profile and corresponding layer thickness. • An escalating value of Pr diminishes the temperature profile for both fluids. [ABSTRACT FROM AUTHOR]

The influence of entropy generation on aligned magnetic flow-including nanoparticles through a convectively heated radial stretched surface in the existence of Cattaneo–Christov heat flux is inspected. The highly nonlinear leading PDE's via the similar scaling transformation are developed. The resulting system via the bvp4c technique from Matlab is computed. The impacts of rising constraints on the liquid velocity, nanoparticles concentration and temperature profile are argued and showed via portraits and table. In addition, the performance of liquid flow is inspected through the friction factor, the mass and heat transfer rate. With the rise in the thermal relaxation constraint, the thermal boundary layer is appreciably altered. Due to an aligned angle, the velocity of nanoliquid declines, while the concentration and temperature of nanofluid augment. It is also observed that the values of friction factor increase, whereas the values of heat and mass transfer decline due to an aligned angle. Entropy generation profiles developed due to magnetic parameters and the aligned angle. Lastly, a comparative scrutiny is composed via the previous studies which lead to support for our presently developed model. [ABSTRACT FROM AUTHOR]

The present research examines the impact of second-order slip with thermal and solutal stratification coatings on three-dimensional (3D) Williamson nanofluid flow past a bidirectional stretched surface and envisages it analytically. The novelty of the analysis is strengthened by Cattaneo–Christov (CC) heat flux accompanying varying thermal conductivity. The appropriate set of transformations is implemented to get a differential equation system with high nonlinearity. The structure is addressed via the homotopy analysis technique. The authenticity of the presented model is verified by creating a comparison with the limited published results and finding harmony between the two. The impacts of miscellaneous arising parameters are deliberated through graphical structures. Some useful tabulated values of arising parameters versus physical quantities are also discussed here. It is observed that velocity components exhibit an opposite trend with respect to the stretching ratio parameter. Moreover, the Brownian motion parameter shows the opposite behavior versus temperature and concentration distributions. [ABSTRACT FROM AUTHOR]